War and the Environment

April 10, 2015Sarah DeWeerdt / The WorldWatch Institute

Several recent wars in different parts of the world reveal that the ecological consequences of war often remain written in the landscape. The story is not always straightforward or clear. Instead, the landscape is like a palimpsest -- a parchment written on, scraped clean, and then written over again -- on which the ecological effects of war may be overlain by postwar regeneration or development. Yet looking carefully can allow the history of past human conflicts to be read in the landscape.

War and the EnvironmentWar can wreck landscapes and ecosystems as well as peopleSarah DeWeerdt / World Watch Magazine, Volume 21, No. 1

(January/February 2008) -- In 1998, the environmental group Green Cross International sent a team of four scientists to Kuwait to investigate the environmental effects of the Gulf War seven years earlier. What the team found was very different from the surreal inferno of burning oil wells that had been the scene in 1991: a quiet desert, green with waving grasses.

As the team wrote in its report, however, "other problems are literally below the surface and one needs only to scratch the desert to find the remains of the continuing environmental damage" -- for example, spilled oil that continued to percolate through the porous soil and threaten Kuwait's meager freshwater aquifers.

Several recent wars in varied environments and different parts of the world reveal that the ecological consequences of war often remain written in the landscape for many years. But the story is not always straightforward or clear. Instead, the landscape is like a palimpsest -- a parchment written on, scraped clean, and then written over again -- on which the ecological effects of war may be overlain by postwar regeneration or development. Yet looking carefully and in the right places can allow the history of past human conflicts to be read in the landscape.

Of course, wars are not the only events that leave their signature on the land. "This is essentially true of all impacts on ecosystems," says John Hart, a conservation scientist based in the Democratic Republic of the Congo-floods and hurricanes, for example. "So it really puts conflict into the context of natural history."

Still, warfare is not the same as other disturbances that buffet natural ecosystems, and there are reasons to be concerned about the longterm ecological effects of war, particularly of the modern variety. For one thing, there is the sheer firepower of current weapons technology, especially its shock-and-awe deployment by modern superpowers: "Our capacity to destroy now is so much greater than it's ever been before," notes World Conservation Union chief scientist Jeffrey McNeely.

The involvement of guerrilla groups in many recent wars draws that firepower toward the natural ecosystems-often already circumscribed and endangered ones-where those groups take cover. And the targeting of civilians can touch off mass migrations of refugees, which on an overcrowded planet can have a devastating environmental effect.

Orange: Anti-Green
Widespread concern about the environmental effects of warfare began with the American war in Vietnam, during which the US military sprayed 79 million liters of herbicides and defoliants over about one-seventh of the land area of southern Vietnam. A variety of chemical mixtures, code-named according to the colored bands painted on their storage drums, were used.

The most widespread (and infamous) of these was Agent Orange. The primary targets of the program were the country's inland hardwood forests and the mangroves that fringed the Mekong Delta, and the primary goal was to deprive communist Viet Cong guerrillas of the cover that enabled them to move freely and launch ambushes against American forces.

US actions in Vietnam gave rise to the concept of "ecocide"-the deliberate destruction of the environment as a military strategy. Yet as McNeely puts it, "Certainly the use of chemical weapons like Agent Orange in Vietnam was incredibly destructive, but not without precursors." In fact, the US spraying program was inspired by an earlier British effort to quell an insurrection in Malaya by chemical spraying to destroy jungle crops planted by rebels.

And the environment has been war's victim, both deliberate and incidental, at least since the beginnings of recorded history. Five thousand years ago, warring Mesopotamian city-states breached dikes to flood the fields of their enemies (a tactic that resonates with recent events in that part of the world). The Hebrew Bible records in the Book of Judges that King Abimelech salted the fields of Shechem; the Romans did the same after they sacked Carthage.

Yet the scale and destructiveness of the US program (code named Operation Trail Dust but better known as Operation Ranch Hand, which referred specifically to the Air Force component) was largely unprecedented. An estimated 35 percent of southern Vietnam's inland hardwood forest was sprayed at least once. Some areas -- those bordering roads and rivers, around military bases, and along the forested transport route known as the Ho Chi Minh Trail -- were hit up to half a dozen times.

Two to three weeks after being sprayed with defoliants, the trees would drop their leaves, generally remaining bare for several months after. That was a boon to the US military but a disaster for these tropical forests, where the canopy holds the great reservoir of biodiversity: plants growing on plants, thousands of kinds of insects, hundreds of birds.

Forest ecologist Arthur Westing, who was instrumental in drawing public attention to the ecological consequences of the Vietnam War, wrote in 1971, "I suspect that the only satisfied animals, at least for a time, would be the termites."

That's because with each spraying some portion of the trees failed to recover. Estimates ranged from about 10 percent in some forests sprayed only once to 80 percent or even more in those sprayed repeatedly. Denuded areas sometimes became desert-like, with blowing sand dunes.

Vietnam's coastal mangrove forests fared even worse: by a quirk of physiology, a single spraying could wipe out almost the entire plant community. Mangroves can live where other species cannot, at the brackish interface of land and sea, because their roots filter the salt out of seawater so that fresh water is drawn up into the plant's leaves. The defoliants interfered with this filtering mechanism and allowed lethal doses of salt to accumulate in the plants.

Worse, the vegetation seemed utterly unable to regenerate, leaving bare mudflats even years after spraying. Westing described the sprayed mangrove areas as "weird and desolate." Ecologists Gordon Orians and E.W. Pfeiffer, who traveled by Navy patrol boat through the Rung Sat Special Zone in 1969, reported in the journal Science that while cruising for several hours through the channels they observed only 64 birds belonging to 12 species -- where they would have expected hundreds of birds representing perhaps 80 species. The only other vertebrate they saw was a lone crocodile on a mud bank. Pfeiffer later recalled "a vast gray landscape, littered with the skeletons of herbicide-killed mangroves."

By some estimates, half of southern Vietnam's mangroves were killed by defoliants. Yet ironically, some of the targeted forests owed their existence to an earlier conflict, says environmental historian David Biggs of the University of California-Riverside. In the U Minh Special Area of the southwestern Mekong Delta, extensive draining and clearing of mangrove swamps had taken place in the early decades of the twentieth century, as French colonial authorities carved out immense rice plantations.

When the Vietnamese struggle for independence got under way after World War II, Viet Minh guerrillas established a base in the area. They breached dikes, reflooded the swamps, and planted palms and mangroves to provide them with cover.

"The rebels didn't have any sort of Western conservationist attitude towards that environment-instead it was more of an engineer's attitude," Biggs says. Yet the result was the dense tangle of native vegetation that later became the target of Agent Orange.

After the departure of US troops in 1975, Vietnam was largely closed to Western scientists for the better part of two decades. Vietnamese scientists, meanwhile, were occupied with rebuilding their country, and in any case lacked access to Western peer-reviewed publications to disseminate their studies.

As a result, the chain of ecological cause-and-effect in postwar Vietnam is not always clear, and sorting out what environmental effects of the war persist more than three decades later can be complicated.

In many areas the invasive grasses and bamboo thickets that replaced inland hardwood forests are still present. A mid-1980s study by Vietnamese ecologists documented just 24 species of birds and 5 species of mammals present in sprayed forests and converted areas, compared to 145-170 bird species and 30-55 kinds of mammals in intact forest.

But, says Pam McElwee, assistant professor of global studies at Arizona State University, "it's hard to say conclusively what changes are a direct result of the war."

Are degraded forests a direct consequence of herbicide attack, or are they the result of fuelwood gathering and forest clearing for small-scale agriculture by a war-torn country's desperately poor population? (And couldn't both possibilities be considered to reflect the ecological effects of war?)

John MacKinnon, a conservation scientist who has worked extensively in Vietnam and elsewhere in Asia, says post-war activities are to blame: "In all cases the failure to recover is because there [have been] continued fires, grazing, and wood harvesting that prevent proper regeneration."

On the other hand, McElwee argues that there are some areas where "it's pretty clear that a change in forest composition is a direct result of the war," citing as examples the Ma Da forest near Ho Chi Minh City, where the typical pattern of forest interrupted by scrubby bamboos and invasive grasses persists despite relatively little recent slash-and-burn agriculture, and the hard-hit A Luoi Valley of central Vietnam. "Some areas that were heavily sprayed continue to be very degraded in terms of the vegetation," she says.

The picture is similarly complex in the mangrove forests. An estimated 105,000 hectares of mangroves were lost to defoliants during the war. The Vietnamese undertook extensive restoration efforts during the 1980s, but many of the replanted areas-about 101,000 hectares, or one-third of the mangroves' total extent-have recently been cut down for the development of aquaculture enterprises. In other words, the effects of the war just a few decades ago are already overlain by multiple layers of ecological change.

Yet a new investigation by Vietnamese forester Phung Tuu Boi offers some clarity. He has analyzed recent satellite photos of Vietnam, and found that images from both hardwood forests and mangrove areas show areas of altered vegetation-in long, straight strips that correspond precisely to the flight paths of the C-123 cargo aircraft that did most of the spraying. "There is no way all these vegetation changes could be attributable to locals setting fires or cutting forests given these striped patterns," McElwee says.

Collateral Damage
Like the Vietnam War, a majority of conflicts worldwide in recent decades have involved guerrilla forces, who may not be numerous or well-equipped but who find an advantage in remaining invisible to their enemies, whether by melting into the civilian population or by taking cover in, for example, dense forests. In turn, the places where guerrillas take cover draw fire.

So while scorched-earth tactics in the ancient world frequently were directed against croplands, today's armies are targeting more-or-less natural ecosystems.

The recent Rwandan and Congolese civil wars have been typical of such conflicts. The Rwandan civil war began in October 1990, when exiles belonging to the Tutsi ethnic group invaded from Uganda and launched an effort to overthrow the Rwandan government, then controlled by the rival Hutu ethnic group.

The conflict led, in 1994, to the Rwandan genocide, in which 800,000 Tutsis and moderate Hutus were murdered. The killings set off the most massive population movement in history, with nearly 2 million Hutus fleeing Rwanda over the course of just a few weeks to refugee camps in Tanzania and Zaire (now the Democratic Republic of the Congo).

In turn, the presence of refugees exacerbated ethnic tensions in Zaire and touched off the first Congolese civil war in 1996. After a brief lull, a second Congolese civil war erupted in 1998. Formally, this conflict ended in 2003, but skirmishes between various armed groups continue to this day. Together the two Congolese civil wars represented the deadliest conflict since World War II.

The Virunga Volcanoes region has been at the center of all these events. Located at the interface of three East-Central African countries-Rwanda, Uganda, and the Democratic Republic of the Congo (DRC)-the Virungas region consists of three contiguous national parks (one in each country) protecting a total of 4,500 square kilometers.

The DRC's section, Virunga National Park, was established in 1925 as Africa's first national park-and was also the first UN World Heritage Site to be declared endangered, in December 1994, because of armed conflict.

In a world already heavily shaped by human hands, the forests and other landscapes that can offer cover to guerrilla groups often represent remnants of natural ecosystems, may have protected status, and frequently harbor endangered species.

That raises the stakes when war breaks out, John Hart says: "Protected areas can be depleted, species driven to extinction, etc.... As conservationists, our ‘victories' are only temporary.... But our losses loom definitive…."

The Virungas represent all of these trends. The region's forests-islands of natural habitat in one of Africa's most densely settled regions and one of the last bits of a once-vast forest ecosystem that blanketed mountains from the Red Sea to southern Africa-were used by both regular army units and rebel groups throughout the recent conflicts in Rwanda and the DRC.

And in turn, that made the forests a target of military attack. In 1991, the Rwandan army cleared a swath of vegetation up to 100 meters wide along a key trail through bamboo forest, in order to reduce the threat of ambush by rebel groups. On the Congolese side, in 1999 the army of the DRC clear-cut a corridor along the main road between Goma and Rutshuru, which runs through Virunga National Park.

Although carried out on a much smaller scale, these events were motivated by the same concerns as the US herbicide program in Vietnam: to deny cover to a forest-based enemy.

When civilian populations are swept up in and displaced by armed conflict, the effects on the environment can be as great as those of direct military activities. For two years beginning in late 1994, for example, about 720,000 Rwandans inhabited refugee camps on the fringes of Virunga National Park. They all needed wood for cooking fires and for building shelters, and some also earned extra money by manufacturing charcoal.

As a result, up to 80,000 people entered the park and carted away up to 1,000 tons of wood every day. By mid-1996, 105 square kilometers of forest had been affected to one degree or another by their activities; 35 square kilometers had been stripped bare.

Yet the effects of these various episodes of deforestation have been relatively minor and short-lived, an indication that the ecological effects of war depend not just on military activities and other war-related events, but also on the specific ecology of a place. The bamboo forest that was cleared by the Rwandan army in 1991 grows very fast, and José Kalpers of the African Parks Foundation says that today the area has "recovered completely."

As for the refugees, most of the trees that they felled were in the park's lava-field forests, relatively species-poor environments and ones where the tree species are adapted to frequent disturbance by fresh lava flows and are therefore capable of quick recovery. "So I think we were really lucky to preserve the other side of the forest!" Kalpers says -- that is, older, more pristine forest that provides critical habitat for the imperiled mountain gorilla.

If the refugee camps had been near a different part of the park, the results could have been quite different. Still, Kalpers cautions, "If the impact of this crisis can indeed be seen as ‘relatively minor' in retrospect, one cannot ignore that this crisis was just one episode in a very long and painful series of events that are still unfolding these days."

The lasting consequences of war in the Virungas region may be more subtle, not necessarily altering the ecosystem as a whole but affecting the animal species in it, particularly large mammals. The deforestation along the Goma-Rutshuru road disrupted a key ecological corridor that crosses the road and links two sectors of Virunga National Park.

Emmanuel de Merode, chief executive of Wildlife Direct, says, "The clearing was not on a large scale, but the corridor is critical to elephant and other large mammal movements, such as buffalos." In turn, disruption of the elephants' usual movement patterns by deforestation and other military activities has led to "increased tree cover in the Semliki Valley and on the Rwindi Plains."

Poaching by armed groups, refugees, and local residents around the park may also have lasting effects on a number of mammal species. The danger is magnified by the fact that armed conflict, especially civil conflict, leads to the widespread possession of automatic weapons, which are vastly more efficient and devastating than traditional hunting weapons such as snares and spears.

Over the course of two months at the end of 1996, for example, Mayi-Mayi rebels killed almost the entire population of hippopotamus on the Rutshuru and Rwindi Rivers. According to de Merode, as a consequence of this and other poaching episodes, "There has been a massive change in vegetation assemblages around Lake Edward."

He cites the collapse of the hippo population as one of the most significant war-related events for the longterm ecology of the Virungas region, noting that it could lead to irreversible vegetation changes, major declines in fish production, and a consequent blow to the fisheries-dependent economy of the DRC's North Kivu region.

Because automatic weapons tend to remain in circulation after hostilities end, poaching may continue and sometimes even increase. Hart says that in the DRC, "the ‘post conflict' context is proving even more of a challenge to the environment than the open declared period of war."

For example, while the mountain gorilla population in Virunga National Park emerged largely unscathed from a decade-plus of war, at least nine gorillas have been killed in 2007 alone. The killings are linked to as-yet-unidentified armed groups operating in the area.

The Swamps in the Quagmire
While armed groups and local residents often take advantage of the chaos and anarchy surrounding wartime to exploit natural resources, the opposite recently occurred in Iraq, as communities in the south of the country responded to the fall of Saddam Hussein's regime in 2003 by beginning to restore one of the world's great wetland ecosystems.

Located at the confluence of the Tigris and Euphrates rivers, the Mesopotamian marshes once stretched over 20,000 square kilometers of interconnected shallow and deep-water lakes, mudflats, reed marshes, seasonal lagoons, and salt-tolerant scrub.

Believed by many to be the site of the Garden of Eden, the largest wetland ecosystem in the Middle East was home to the 5,000-year-old Marsh Arab culture, formed a crucial stop for many millions of migratory birds traveling between Siberia and Africa, and provided nursery grounds for economically important Persian Gulf fish and shrimp, as well as other marine and freshwater species.

"The Mesopotamian wetlands are probably one of the most crucial areas in the region in terms of biodiversity," says Peter Zahler, Wildlife Conservation Society Asia Program assistant director.

It is an ecosystem that has been shaped and reshaped by conflict repeatedly in recent decades. The Iran-Iraq border runs through the marshes, which were a main theater of the 1980s war between those two countries. Both sides used the waters strategically-building dikes, draining some areas to facilitate their own troop movements, and flooding others to stop the enemy.

But the real disaster for the marshes struck in the early 1990s, when Saddam Hussein's regime drained them in response to a Shia uprising that had spread through southern Iraq after the Gulf War. By the year 2000, a series of dikes and channels had reduced the marshes to less than 10 percent of their original extent, transforming the landscape into a parched desert covered by salt crusts over a meter deep in some areas.

Local temperatures increased by 5 degrees Celsius, siltation damaged coral reefs in the Persian Gulf, and dust storms plagued the land. Several species endemic to the marshes-the smooth-coated otter, the bandicoot rat, the long-fingered bat, and a species of barbel fish-are thought to have been driven extinct. Dozens more bird species were placed in danger of disappearing forever, and Persian Gulf fish and shrimp landings declined.

But in the summer of 2003, dramatic satellite images showed water pouring in great fans over the dessicated marshlands, after local people attacked Saddam's dikes with shovels and backhoes. Now an extensive international effort, including US, Canadian, British, Italian, Japanese, and Iraqi groups, aims to restore the ecosystem.

By March 2004, about 20 percent of the marshes' former area had been reinundated, and the waters reached about 40 percent of their previous extent by November 2005. Satellite pictures also showed substantial growth of reeds, the dominant native vegetation in large areas of the marshes, late that year.

"As we speak about 65 percent of the marshes is covered with water, and about 50 percent of that is in a state of robust recovery," says Azzam Alwash, CEO of Nature Iraq and a leader of the marsh restoration effort. "And fortunately the reeds are hardy. All you have to do is introduce water and the seeds in the soil just bloom. It is amazing!"

As native vegetation has returned to the marshes, wildlife has followed. Bird surveys in 2005 found 72 species of birds, including 10 regionally or globally threatened species, taking up residence in the area. Several endemic species, including the Basrah reed warbler and the Iraq babbler, now have a chance at survival.

The future of the marshes is hardly certain. High soil salinity and stagnant water may limit the possibilities for restoration in some areas of the marshes. A series of dams upstream -- both the Tigris and the Euphrates originate in Turkey -- has diminished the flow of these two rivers over the twentieth century, and dampened the pulse of spring snowmelt that previously nourished the marshes with nutrients and alluvial soil. Alwash's group is working on a hydrology plan for the marshes to head off some of these problems.

Alwash, a civil engineer who was born in southern Iraq and spent over two decades as an expatriate in the United States, says, "Without this conflict, without the removal of Saddam, the restoration of the marshes would have been impossible."

Because of the rebirth of the marshes, as well as the shutdown (if temporary) of nearly 200 industrial plants that had spewed effluent into the Tigris and Euphrates, he concludes, "Generally speaking ... this war's effect on the environment has been positive."

What scientists know about other environmental effects of the current conflict in Iraq remains largely speculative at this point, and mostly based on studies of the 1991 Gulf War, which involved similar actors, munitions, and environments.

The most vivid images of environmental destruction during that previous conflict came from sabotage of Kuwaiti oil fields. Retreating Iraqi troops set 630 oil wells alight, generating a plume of toxic black smoke several hundred kilometers wide and long.

"You'd go to places downwind and it would be covered with specks of oil and carbon," recalls Matthew Naud, then an environmental consultant working on contract with the US Environmental Protection Agency who spent six weeks in Saudi Arabia and Kuwait in 1991. Soot and oil droplets covered 953 square kilometers of desert, damaging the fragile vegetation and leading to widespread degradation of rangelands in Saudi Arabia.

Naud, who was also a member of the Green Cross International team, recalls that in heavily oiled areas of the Kuwaiti desert "there wasn't much sign of life" in 1998. In less affected areas, where annual desert grasses had largely recovered, perennial plants were still mostly absent.

And where saltwater was used to put out the flames, native vegetation has been replaced with salt-resistant coastal species. "My impression is that damage to arid environments is often longer lasting, simply because of the fact that plant regeneration is so slow," Zahler says. "The effects can last for decades and decades. Centuries."

Despite fears that widespread oil-well fires would occur during the current conflict, just nine well-head fires in Iraq's southern Rumallah oil fields were identified in the early days after the US invasion.

However, oil-filled trenches set alight in Baghdad to interfere with satellite surveillance and targeting of laser-guided munitions would create the same sort of contamination by soot and oil mist in ecosystems downwind. And sabotage of pipelines and other oil infrastructure by insurgents would lead to oil spills similar to those that now threaten Kuwait's aquifers.

Perhaps a greater worry is physical damage to the desert, particularly the millimeter-thin layer of microorganisms that forms a crust at the top of the soil, protecting it from erosion. "If you don't disturb that, the amount of dune formation is limited," explains Naud. "And what you learn quickly is if you have tanks and trucks and vehicles like that driving all over a desert, you've broken up this crust."

Remote sensing analyses led by Farouk El-Baz of Boston University showed that the Gulf War resulted in an increase in sandstorms and dune formation in the region. El-Baz reports that today "sand continues to accumulate on dunes, which also continue to move down-wind."

In fact, the effects of physical disruption of the desert can be a lot longer lasting than that: tracks from World War II tanks are still visible in some areas of the North African desert, and one study in Arizona suggested that desert crusts might take a thousand years to fully recover from the movements of heavy vehicles.

Jeffrey McNeely points out that warfare is likely to have the most severe, longest-lasting effects on protected areas that harbor endangered species, and slow-to-recover ecosystems such as deserts. Even in the most fragile environments, sometimes nature-and people-can surprise us, as the Mesopotamian marshes' recovery shows. But turn and look in another direction and you are likely to see warfare's enduring scars.

According to El-Baz, dust storms and sand dune formation, similar to what occurred in the wake of the Gulf War, are also likely effects of the movements of military vehicles through the desert during the current Iraq war. Of the dunes, El-Baz says, "These would continue to move for as long as the wind blows."

Sarah DeWeerdt is a Seattle-based science writer specializing in biology and the environment.

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